A machining simulation has been widely used in performing cutting work using an NC machine tool, in order to examine whether a desired shape can be formed correctly with an NC program that has been created and prepared. However, in a case where a problem with the machining is found after executing the machining simulation, the machining simulation often needs to be executed repeatedly in order to analyze the cause of the problem and/or make a solution to the problem.
In cutting work, a workpiece originates from a state of raw material, and undergoes successive cutting done by individual movements of a tool, which leads to a shape of a final result of the cutting work. Therefore, it is difficult in a machining simulation that simulates the cutting work to advance the simulation while skipping a midway process thereof. It is common to re-execute the simulation from the beginning of the cutting work each time the simulation is repeated.
Cutting-deformation processing on a three-dimensional shape model of a workpiece, which is performed in a computer during a machining simulation, requires a long calculation time that is not negligible. Therefore, in a case where a found problematic point appears near the end of the machining, for example, a considerable amount of a waiting time is required until the problematic point can be checked, and therefore there has been a problem that examination work cannot be performed efficiently.
An invention setting solving this problem as its object is disclosed in Patent Literature 1. According to the invention disclosed in Patent Literature 1, in a machining composed of a plurality of steps, after a stimulation result (pixel data) of a final state at each of the steps is saved, the simulation result at a step immediately before the step at which a simulation is restarted is read, and the simulation is executed from that point. Therefore, examination work can be performed more efficiently as compared to the case where a machining simulation is executed from the beginning of the machining.